Improvement in steam-engines



liilNITnD STATES PATENT OFFICEO JAMES R. MAXWELL AND EZRA COPE, OFCINCINNATI, OHIO.

IMPROVEMENT IN STEAM-ENGINES.

Specification forming part of Letters Patent No. 56,242, dated July 10,1866.

To all whom it may concern:

Be it known that we, JAMES R. MAXWELL and EZRA COPE, of Cincinnati, inthe county of Hamilton, and in the State of Ohio, have invented anew andImproved Plan for Constructing SteamEngines; and we hereby declare thatthe following is a full, clear, and exact description of the same,reference being had to the accompanying drawings,'ibrming part of thisspecification, in which- Figure l is a vertical section lengthwisethrough the steam-cylinder, piston, and valve, with the piston at theend of its stroke, and the valve in the act of moving for a returnstroke. Fig. 2 is a horizontal section through the steam-cylinder andvalve, with the piston in the middle of the cylinder and moving to theleft, with the valve in the proper position for completing the stroke.Fig. 3 is a crosssection through the cylinder, piston, and valve in theline l l, Fig. 2, showing the main steam supply and exhaust ports. Fig.4L is a crosssection through the cylinder,piston, and valve in the line2 2, Fig. 2, showing the main steam supply and exhaust ports. Fig. 5 isa horizontal section of the main piston with the valve removed, showingthe steam-ports for supply and exhaust for main and valve cylinders;

The nature of our invention consists in the construction of a steam-engine with a cylinder and piston suited to each other, so as to have thepiston perform the function ofV a valve in opening and closing the portsof steam-passages, when accomplished by making the piston as much longerthan the stroke as is required to cover the ports at each end of thecylinder alternately when in operation; also, in the arrangement ofsteam-passages to the interior of such a piston as described, wherein amain piston-valve is so arranged with its passages and cavities as toproperly communicate with the passages in the piston to change anddirect the low of steam in order to effect the reciprocating motion ofthe piston without external valve-gear.

To enable others skilled in the art to make and use our invention, wewill proceed to describe its construction and operation.

The main cylinder A is provided with a steam-connection, J, on top andexhaust-pipe I at the bottom, near the center, between the ends, and hasa channel, U' U" ,near each end in its inner surface, which, whencovered by the piston B, forms steamways for operating the valve C, ashereinafter described. There is a small side pipe and valve, P P,leading from the high steam-pipe J to one end of the cylinder A, usedfor starting the engine should the valve C cover the ports F F. For-pumpin g-engines this cylinder has a foot in the middle, serving forthe exhaust; also supports the cylinder. The piston B is a long cylinderturned to lit the bore of the cylinder A accurately, and has heads M Mscrewed into its ends, to one of which the piston-rod V is attached.

In each side of the piston is a channel, E E, longer than the stroke ofthe engine, one of which communicates with the high steam-pipe J. In thecenter of each channel is a port,L, through which steam passes into andthrough the valve C to the opposite one7 by which one port balances theother. Near the bottom of the piston is a channel, H, longer than thestroke, with a port, G, in the middle for the escape-steam. Near eachend of the piston are two small ports, N' N Ol O. The ones nearest theends pass over the recesses U U alternately for supplying steam to theinterior of the piston B for moving the cylindrical valve C. The ports OO" are for exhausting the steam from the valve, the recesses U U in theinner surface of the main steam-cylinder, reaching from the highsteam-channel E in the side of the piston B to convey steam to thevalve-chamber. The guides W W in the piston and valve are to keep themfrom turning round, so that the ports may, always be in proper positionwhen the piston and valve move back and forth.

To operate, steam is admitted from the source of supply and passes intoJ on top the cylinder A', Fig. 1, and around channel J, Fig. 3, intochannels E E" in the piston B, Figs. 2, 3, 4, 5, through openings L L tosteam-passage L L, Fig. 2. The main piston B', Fig. l, is represented ashaving completed its stroke to the right, and the valve C is receivingsteam for the return stroke, Fig. l, from port N, through recess U andchannel E, which will move the valve C to the left, as shown in Fig., 2,thereby bringing port L, Fig.. 2, in communication with F for supply,and port G with channel El for exhaust, Figs.3,5; thence to opening I,Figs. 3, and to the atmosphere, as indicated by the black (rrow, Fig. 3,at the same time that the piston B has come into position to admit steamto the valvechamber D by bringing,` port N" over recess U for supply.The steam is exhausted from the opposite end oi' D by port O coming overI, which leaves the valve free to move to the exhausted end until itpasses `over the exhaustport O, when it begins to cushion on the Steamor air contained therein, and gradually stops the valve. The main pistonB will move in the direction ofthe arrow, Fig. 2, by virtue of thesupply-steam, until it reaches the ond of its stroke, when the reversemotion takes place in the same manner as before described. Should thevalve C stop in a position to close the ports F F, steam is admitted byvalve P and side pipe, P, Fig. 1, into the main cylinder A, moving thepiston B to the opposite end, when the valve G will be set aright, andthe piston will move back an d forth continuously as long as steam issupplied.

What we claim as our invention, and desire to secure by Letters Patent,is-

l. The piston-head of a steam-engine longer than its stroke, in themanner and for the purpose herein described.

2. rlhe piston-head of a steam-engine longer than its stroke, withchannels and ports in its sides, in combination'with a cylinder havingcorresponding added length and ports leading,` to and from the mainsteam-valve, in the manner and for the purpose substantially asdescribed.

3. The cylindrical piston-valve @,With closed ends, and steam-openingsthrough its sides and bottom, whereby to operate Within the main piston,substantially as described.

4. The independent steam pipe and valve P P, for admitting` steam to themain piston B in cylinder A, in the manner and for the purpose hereindescribed.

JAS. MAXWELL. EZRA corn.

Witnesses N. MARCHANT, GEORGE W. CARR.

